Self-elevating wind power platform leg replacement method

Abstract

The present invention relates to the field of the construction of wind power platforms, and provides a method for replacing the leg of a jack-up wind power platform. The method includes: dividing the old leg into a first-section old leg, a second-section old leg, and a bottom old leg; removing the first-section old leg, the old pile shoe, and the bottom old leg; taking out the pile fixing chamber on the second-section old leg, and removing the second-section old leg; discharging the dock piers, and placing the new pile shoe on the temporary dock piers; lowering and locking the bottom new leg through the locking device of the platform leg pin cylinder; hoisting the first-section new leg and the second-section new leg by a floating crane. The method for replacing the leg of the jack-up wind power platform provided by the present invention disassembles the old leg in sections and installs the new leg in sections, reducing the requirements for the lifting crane; different methods are adopted for different parts of the old leg to improve the disassembly efficiency of the old leg; after removing the first-section old leg, the old pile shoe is removed and transferred in the dock, ensuring safety.

Description

Technical Field

[0001] The present invention relates to the field of construction of wind power platforms, and particularly to a method for replacing the leg of a jack-up wind power platform. Background Art

[0002] With the global energy shortage and the increasingly serious environmental pollution, wind power generation, as a pollution-free renewable energy, has developed rapidly. Due to the limited land space and the large wind energy density at sea, the development of offshore wind energy has been increasingly emphasized. Among them, a jack-up offshore wind power installation platform raises the platform to a certain height through the cooperation of legs and a lifting system to adapt to different water depths and operating heights.

[0003] In recent years, the scale of wind turbines has become larger and larger, which makes the traditional wind power installation platform unable to meet the requirements, and it is necessary to replace the legs of the wind power installation platform. If only the legs are removed according to their length and weight, not only is the efficiency low, but there is also a possibility of the pile shoe falling off when lifting the bottom leg, causing unnecessary significant economic losses and even casualties. Summary of the Invention

[0004] The present invention provides a method and a system for replacing the leg of a jack-up wind power platform, aiming to provide an efficient method for replacing the leg.

[0005] In a first aspect, the present invention provides a method for replacing the leg of a jack-up wind power platform, including:

[0006] According to a preset rule, the old leg is sequentially divided into a first-section old leg, a second-section old leg, and a bottom old leg; the bottom old leg is the part of the old leg connected to the old pile shoe;

[0007] Remove the first-section old leg;

[0008] Steer the ship into the dock, and remove the old pile shoe and the bottom old leg;

[0009] Steer the ship out of the dock, take out the pile fixing chamber on the second-section old leg, and remove the second-section old leg;

[0010] Steer the ship into the dock, arrange the dock piers according to a preset drawing, place the new pile shoe on the temporary dock piers, and install the crescent plate and the panel on the new pile shoe;

[0011] Lower and lock the bottom new leg through the platform leg pin cylinder locking device, and adjust the position of the new pile shoe to align the positioning cross marks of the new pile shoe and the bottom new leg;

[0012] Steer the ship out of the dock, hoist the first-section new leg and the second-section new leg by a floating crane, and weld the joint between the legs.

[0013] In one embodiment, the removal of the old pile shoe and the bottom old pile leg includes:

[0014] Lower the remaining part of the old pile leg by a first preset distance through a lifting mechanism, and place wood between the bottom plate of the old pile shoe and the dock bottom;

[0015] Fix the remaining part of the old pile leg through the pin of the lifting mechanism, and cut the barrel walls of the old pile leg and the old pile shoe to make the old pile shoe fall off;

[0016] Remove the pile leg with a first preset length under the bottom old pile leg, and lower the remaining part of the old pile leg by a second preset distance through the lifting mechanism;

[0017] Remove the pile leg with a second preset length under the bottom old pile leg, and raise the old pile leg by a third preset distance through the lifting mechanism, that is, complete the removal of the bottom old pile leg;

[0018] Drain the water in the dry dock, and move the old pile shoe to the dock entrance, that is, complete the removal of the old pile shoe.

[0019] The hoisting of the second new pile leg by a floating crane includes:

[0020] After hoisting the second new pile leg by a floating crane for a fourth preset distance, check the hook, signal, and control device of the floating crane, and check the lifting lug and structure of the second new pile leg;

[0021] After the second new pile leg is made upright, remove the sling at the lower end of the second new pile leg;

[0022] Lift the second new pile leg by the floating crane and move the second new pile leg to the platform hoisting position;

[0023] Adjust the front, rear, left, and right directions of the second new pile leg and the direction of the segmented positioning tooling, and lower it into the total pile leg positioning tooling.

[0024] After welding the joint between the pile legs, it further includes:

[0025] Perform flaw detection on the welded part;

[0026] Perform platform pile insertion.

[0027] Before successively dividing the old pile leg into the first section of old pile leg, the second section of old pile leg, and the bottom old pile leg according to a preset rule, it further includes:

[0028] Precast the new pile leg in segments to obtain the first section of new pile leg and the second section of new pile leg;

[0029] Precast the new pile shoe and the bottom pile leg integrally.

[0030] The segmented prefabricated new leg includes:

[0031] Fabricate a single - cylinder - section leg;

[0032] Lengthen two single - cylinder - section legs and then assemble multiple cylinder sections.

[0033] The process of assembling multiple cylinder sections includes: positioning the reference cylinder on the jig, butt - joint positioning of cylinder sections, circumferential - joint assembly of cylinder sections, circumferential - joint welding, circumferential - joint flaw detection, post - welding precision measurement, installation of outfitting parts, and painting of leg segments.

[0034] The prefabricated new pile shoe includes:

[0035] When prefabricating the new pile shoe, sacrificial anodes, a punching system, and outfitting parts are installed synchronously.

[0036] The method for replacing the leg of a jack - up wind power platform provided by the present invention divides the old leg into the first - section old leg, the second - section old leg, and the bottom old leg; removes the first - section old leg; sails the ship into the dock, removes the old pile shoe and the bottom old leg; sails the ship out of the dock, takes out the pile - fixing chamber on the second - section old leg, and removes the second - section old leg; sails the ship into the dock, arranges the dock piers according to the preset drawing, places the new pile shoe on the temporary dock piers, and installs the crescent plate and the panel on the new pile shoe; uses the locking device of the platform - leg pin cylinder to lower and lock the bottom new leg and adjust the position of the new pile shoe; sails the ship out of the dock, hoists the first - section new leg and the second - section new leg by a floating crane, and welds the mating joints between the legs.

[0037] The method for replacing the leg of the jack - up wind power platform has the following advantages: The old leg is removed in segments and the new leg is installed in segments, reducing the requirements for the hoisting crane; different parts of the old leg are removed in different ways, improving the removal efficiency of the old leg; the bottom new leg is locked by the locking device of the platform - leg pin cylinder, improving the installation accuracy; after removing the first - section old leg, the old pile shoe is removed and transferred in the dock, and finally the second - section old leg is removed, ensuring safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] To more clearly illustrate the technical solutions of the present invention, the drawings required for use in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 is a schematic flow chart of the method for replacing the leg of the jack - up wind power platform provided by the present invention;

[0040] Figure 2 It is a schematic diagram of the old leg structure provided by the present invention;

[0041] Figure 3 It is a schematic diagram of the steps for prefabricating the new leg in segments provided by the present invention;

[0042] Figure 4 It is a schematic diagram of the new leg structure provided by the present invention. Detailed implementation manners

[0043] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0044] The embodiments of the present invention provide an embodiment of the method for replacing the legs of a jack-up wind power platform. It should be noted that although the logical order is shown in the flowchart, under certain data, the steps shown or described can be completed in a different order from here.

[0045] Refer to Figure 1 , Figure 1 which is a flowchart of the method for replacing the legs of a jack-up wind power platform provided by the present invention. The method for replacing the legs of a jack-up wind power platform provided by the embodiments of the present invention includes:

[0046] Step 101: Divide the old leg into the first-section old leg, the second-section old leg and the bottom old leg in sequence according to a preset rule; the bottom old leg is the part of the old leg connected to the old pile shoe;

[0047] Step 102: Demolish the first-section old leg;

[0048] Step 103: Drive the ship into the dock and demolish the old pile shoe and the bottom old leg;

[0049] Step 104: Drive the ship out of the dock, take out the pile fixing chamber on the second-section old leg, and demolish the second-section old leg;

[0050] Step 105: Drive the ship into the dock, arrange the dock piers according to a preset drawing, place the new pile shoe on the temporary dock piers, and install the crescent plate and the panel on the new pile shoe;

[0051] Step 106: Lower and lock the bottom new leg through the platform leg pin cylinder locking device, adjust the position of the new pile shoe to align the positioning cross marks of the new pile shoe and the bottom new leg;

[0052] Step 107: Dock the ship. Lift and install the first new leg and the second new leg using a floating crane, and weld the joint between the legs.

[0053] Specifically, the old legs can be sequentially divided into the first old leg, the second old leg, and the bottom old leg according to a preset rule. Here, the second old leg is connected to the bottom old leg, and the bottom old leg is the part of the old leg connected to the old pile shoe.

[0054] It should be noted that the first old leg does not specifically refer to a certain section of the leg, but any leg that is not connected to the bottom old leg. That is to say, the staff can divide the old leg into several sections of old legs according to actual needs, rather than just dividing it into three parts.

[0055] Furthermore, it should be noted that the preset rule is generally: the maximum height of each section of the old leg is 21.55 meters, and the maximum weight of each section of the old leg is 240 tons.

[0056] In the embodiment of the present invention, taking the modification of the "Huaxianglong" wind power platform as an example, the method for replacing the legs of the self-elevating wind power platform of the present invention will be described. In this embodiment, four old legs need to be replaced. Here, the diameter of the old leg is 4.8 meters, and the total height of the old leg is 90m. In this embodiment, each old leg is divided into 5 segments, which are, from top to bottom, the first old leg segment, the second old leg segment, the third old leg segment, the fourth old leg segment, and the bottom old leg segment, with heights of 18.54 meters, 21.55 meters, 21.55 meters, 20.9 meters, and 7.46 meters respectively. Here, the bottom old leg is sleeved with an old pile shoe, and the height of the old pile shoe is 3.6 meters. As Figure 2 shown, Figure 2 is a schematic diagram of the structure of the old leg provided by the present invention.

[0057] Further, remove the first old leg segment and retain the second old leg segment and the bottom old leg segment.

[0058] In the above embodiment, cut the first old leg segment, the second old leg segment, and the third old leg segment from top to bottom in the dock, and use a 600-ton floating crane, a 350-ton crane on the ship, and a 1200-ton crane to lift the segmented old legs off the dock respectively. At this time, the old leg remains the fourth old leg segment and the bottom old leg segment.

[0059] Further, pilot the ship into the dry dock and remove the old pile shoe and the old bottom pile legs. Specifically, lower the remaining part of the old pile legs by a first preset distance through the lifting mechanism, and place wood between the bottom plate of the old pile shoe and the dock bottom; fix the remaining part of the old pile legs with the pins of the lifting mechanism, and cut the cylindrical walls of the old pile legs and the old pile shoe to make the old pile shoe fall off; remove the pile legs with a first preset length under the bottom old pile legs, and lower the remaining part of the old pile legs by a second preset distance through the lifting mechanism; remove the pile legs with a second preset length under the bottom old pile legs, and raise the old pile legs by a third preset distance through the lifting mechanism, thus completing the removal of the bottom old pile legs; drain the water in the dry dock and move the old pile shoe to the dock entrance, thus completing the removal of the old pile shoe. Among them, the first preset distance, the first preset length, the second preset distance, the second preset length, and the third preset distance can all be determined according to the actual situation.

[0060] In the above embodiment, after the ship is piloted into the dry dock for the first time, first lower the old pile legs by about 1.78 meters using the lifting mechanism, then place wood between the bottom plate of the old pile shoe and the dock bottom, and at the same time temporarily fix the old pile legs with the pins of the lifting mechanism. Finally, cut the cylindrical walls of the old pile legs and the old pile shoe, and the old pile shoe falls directly onto the wood on the dock bottom after cutting. Further, destructively remove the 1.3-meter old pile legs above the old pile shoe by means such as shredding, and then lower the old pile legs by about 1.3 meters using the lifting mechanism; destructively remove the 1.3-meter old pile legs above the old pile shoe by means such as shredding, and then lower the old pile legs by about 1.3 meters using the lifting mechanism; destructively remove the 1.26-meter old pile legs above the old pile shoe by means such as shredding, and then raise the old pile legs by about 3 meters using the lifting mechanism. After the lower guide block is completely exposed, inspect the lower guide block. Further, after the dry dock is drained of water, first use a modular vehicle in the dock to move the old pile shoe to the dock entrance, and then use a 600-ton floating crane to lift the old pile shoe onto the dock or barge in sequence. At this time, the remaining part of the old pile legs is the fourth section of old pile legs.

[0061] Further, pilot the ship out of the dry dock, take out the pile fixing chamber on the second section of the old pile legs, and remove the second section of the old pile legs.

[0062] In the above embodiment, after the ship is piloted out of the dry dock for the first time, use the 1200-ton crane on the ship to lift out the pile fixing chamber on the old pile legs, and then place it flat on the dock ground or barge. Further, remove the steel wire rope, hook, shaft pin and accessories of the old boom of the 1200-ton crane, and then use a 500-ton floating crane and a 600-ton floating crane to lift and place the old boom on the barge on the starboard side. Further, use a 600-ton floating crane to remove the fourth section of the old pile legs, thus completing the removal of the old pile legs.

[0063] Further, pilot the ship into the dry dock, place the dock piers according to the preset drawings, place the new pile shoe on the temporary dock piers, and install the crescent plate and the panel on the new pile shoe.

[0064] In the above embodiment, when the ship is dry-docked and the piers are arranged for the second time, a combined pier with a height of 2.45 meters is used at the bottom of the ship. No dock piers are arranged under the new pile shoes. The piers around the new pile shoes and in the bow area are arranged strictly according to the positions and heights required in the pier arrangement drawing. After arranging the piers, it is necessary to apply for inspection by quality control QC and the shipowner. It should be noted that when the ship is dry-docked and the piers are arranged, no dock piers are arranged in the area of the shifting route of the new pile shoes first. The piers are arranged after the new pile shoes are shifted into place. Each new pile shoe needs to be placed 0.9 m to the side on the dock bottom. Among them, the pier arrangement drawing and the shifting route of the new pile shoes can be determined according to the specific situation in the dock. Further, use a 600-ton floating crane to lift 4 new pile shoes to the dock bottom, then use a modular vehicle to move the 4 new pile shoes to below the leg well at the bottom of the ship (0.6 m to the side), and then use a hydraulic positioning machine to place the new pile shoes on the temporary dock piers. Specifically, when the ship enters the dock, the draft at the bow and stern is about 5.0 meters. The highest point of the top of the new pile shoe is 4.912 m from the dock bottom. The stern of the ship enters first. The bow of the ship is about 10.725 meters from the dock gate. The left side of the ship is about 7 meters from the dock wall, and the right side of the ship is about 16 meters from the dock wall. After the new pile shoes are retracted, they protrude 2.1 m from the bottom of the ship and 1.35 m from the side. Further, after the ship is dry-docked and seated in the dock, install the crescent plate and the panel on the pile shoes. After welding, conduct a flaw detection inspection. If the inspection is correct, install the positioning and guiding dock at the cross position of the legs.

[0065] Further, through the locking device of the platform leg pin cylinder, lower and lock the new bottom leg, and adjust the position of the new pile shoe to align the positioning cross mark of the new pile shoe with the new bottom leg.

[0066] In the above embodiment, through the locking device of the platform leg pin cylinder, slowly lower the new bottom leg by 1375 mm (i.e., close the clutch opening by 3 cm), then stop lowering and re-lock the new bottom leg through the locking device of the platform leg pin cylinder. Further, the new bottom leg is locked on the locking device of the platform leg pin cylinder. The fifth new leg is segmented with the foundation section positioning the pile shoe. There are four positioning machine devices on the segmented pile shoe. By adjusting the left, right, front, and back movement of the new pile shoe, align the positioning cross mark of the new pile shoe with the leg. Then, through the up and down adjustment of the positioning machine device, meet the requirement of 200 mm for the two closing inspection lines of the new pile shoe and the new leg, and measure the distance between the well structure of the new pile shoe and the new pile shoe as 150 mm, the distance from the baseline of the ship bottom as 2100 mm, and the distance from the side as 1350 mm. Further, report the precision positioning to quality control QC, the shipowner, and the ship inspection. After passing the inspection, weld according to the "New Pile Shoe Installation and Welding Process". Conduct a flaw detection inspection after welding. It should be noted that the new legs include the first new leg, the second new leg, the third new leg, the fourth new leg, the fifth new leg, and the new bottom leg.

[0067] Further, the ship is driven out of the dock, the first new leg and the second new leg are hoisted by a floating crane, and the joint between the legs is welded. Specifically, after the second new leg is hoisted by the floating crane for a fourth preset distance, the hook, signal, and control device of the floating crane are inspected, and the lugs and structure of the second new leg are inspected; after the second new leg is erected, the sling at the lower end of the second new leg is removed; the second new leg is lifted by the floating crane and moved to the platform hoisting position; the front, rear, left, and right directions of the second new leg and the direction of the sectional positioning tooling are adjusted, and it is lowered into the overall leg sectional positioning tooling. Further, flaw detection is carried out on the welding parts, and after passing, the platform is jacked into the pile.

[0068] In the above embodiment, after the ship is dry-docked for the second time, the fifth new leg is vertically placed at the dock. After the fifth new leg is hoisted by a 1200-ton floating crane to a height of 200 mm, it is stationary for 5 minutes to check whether there are any abnormalities in the hook, signal, control device, etc. of the floating crane, and whether there are obvious deformations in the lugs and structure of the fifth new leg. After the inspection meets the requirements, the fifth new leg is erected by using the cooperation of the large and small hooks of the floating crane. Further, after the fifth new leg is erected, it is about 200 mm above the ground. The sling at the lower end of the fifth new leg is removed. After the sling is removed, the fifth new leg is lifted. The floating crane hoists the fifth new leg and moves it to the platform hoisting position. When at the upper end of the fifth new leg, the front, rear, left, and right directions of the leg and the direction of the sectional positioning tooling are adjusted. After the direction is positioned, the leg is slowly lowered into the overall leg sectional positioning tooling. Further, the joint between the fifth new leg and the bottom new leg is welded and flaw detection is carried out; the first new leg, the second new leg, the third new leg, and the fourth new leg are installed through the same steps. Further, the platform is jacked into the pile with its starboard side against the dock. The pile is inserted 6 m into the mud and the draft is 9 m, that is, the leg below the water surface is 15 m.

[0069] Since the sling is on the outside of the leg and there is a possibility of colliding with the K-Link crane platform, removing the sling after erection can avoid collisions.

[0070] Further, before dividing the old legs into the first old leg, the second old leg, and the bottom old leg according to the preset rules, it also includes: prefabricating the new legs section by section to obtain the first new leg and the second new leg; prefabricating the new pile shoe and the bottom leg as a whole. Specifically, prefabricating the new legs section by section includes: manufacturing a single-barrel leg; joining two single-barrel legs and then assembling multiple sections of the barrel. The process of assembling multiple sections of the barrel includes: positioning the reference barrel on the jig, butt-joint positioning of the barrel sections, circumferential joint assembly of the barrel sections, circumferential joint welding, circumferential joint flaw detection, post-weld precision measurement, installation of outfitting parts, and painting of the leg sections. Prefabricating the new pile shoe includes: overall prefabricating the new pile shoe according to the bottom of the new leg; when prefabricating the new pile shoe, sacrificial anodes, a pile driving system, and outfitting parts are installed synchronously.

[0071] As Figure 3 shown, Figure 3 it is a schematic diagram of the new leg segment prefabrication steps provided by the present invention. In the above embodiment, the diameter of the 4 prefabricated new legs is 4.8 meters, and the total height of each new leg is 105.38 meters. The 100.88 meters of the upper part of the new leg is divided into 5 segments, which are the first new leg segment, the second new leg segment, the third new leg segment, the fourth new leg segment and the fifth new leg segment from top to bottom, with heights of 15.67 meters, 22 meters, 20 meters, 20 meters and 23.21 meters respectively. Among them, the second new leg segment, the third new leg segment, the fourth new leg segment and the fifth new leg segment are prefabricated, and the first new leg segment reuses the old leg. Generally, the maximum height of a single segmented leg is about 28 meters, and the maximum weight of a single segmented leg is about 322.4 tons. It should be noted that the height of the bottom new leg is 4.5 meters, the bottom new leg and the new pile shoe are prefabricated integrally, the bottom new leg is hoisted at the dock, and the new pile shoe is installed in the dry dock. As Figure 4 shown, Figure 4 it is a schematic diagram of the new leg structure provided by the present invention.

[0072] In the above embodiment, when prefabricating the new leg, first make a single cylinder section. The nesting is laid out according to the theoretical length unfolded by the circumference (mid-diameter) of the cylinder, and π is taken as 3.1416. Further, draw the processing reference line, cutting line, inspection line (100 mm away from the net material line), spray and draw the starting rolling edge lines (rolling radius, radian) at both ends on the steel plate structure surface (inner skin), draw the 100 MARK inspection lines and punch marks at the upper and lower mouths of the steel plate outer skin, and mark information such as the upper / lower mouths of the cylinder and the leg number. At the same time, the form of the plate edge groove should be clearly marked. Further, the parts are semi-automatically cut, and the accuracy requirements for cutting are a length deviation of ±2 mm, a width deviation of ±1 mm, and a diagonal deviation of within ±2 mm.

[0073] Further, the preheating temperature can only be cut after being confirmed by the inspector. Before gas cutting the steel plate, remove rust, oil and other impurities within 50 mm of the cutting edge, and remove slag and spatter after gas cutting; when cutting, select a semi-automatic cutting machine and use a neutral flame for cutting; after the groove is opened, check that the surface roughness of the gas cutting is not greater than 25 microns, and there are no defects such as burrs, tearing, and cracks that affect the weld quality and strength.

[0074] Further, start rolling from the ends and mark the equal division lines of the press head: the interval range of the equal division lines is 100 to 120 mm; the length of the press head is not less than 1000 mm. Further, check and adjust the upper and lower dies. The longitudinal parallelism error of the upper and lower dies is less than or equal to 1.0 mm; the surface roughness Ra of the working surface of the lower die is less than or equal to 3.2; the press head is carried out on a 10000-ton press. During the press head process, check the R shape with a pressing template at any time, and control the gap not to be greater than 1.0 mm; during the trial press, check that the indentation depth is not greater than 0.8 mm. If it exceeds, pad softer materials on the upper and lower dies to reduce the indentation depth. Further, cut off the press head allowance: After starting rolling from both ends with a 10000-ton hydraulic press, measure the perimeter at 100 mm from the upper and lower ends of the outer skin and then cut off the allowances at both ends, and prepare the butt submerged arc welding grooves for the longitudinal and circumferential seams.

[0075] Further, roll the steel plate into a circle. Feed the steel plate in the center to a three-roll plate rolling machine, and accurately position the two ends in the length direction on the roller bed. Precision requirements after processing: A) The diameter (outer diameter) tolerance is 4800 +2 / -3 mm; B) The roundness tolerance is less than or equal to 6 mm; C) The straightness tolerance is less than or equal to 1 mm; D) The co-planarity tolerance at the ends is less than or equal to 1 mm; After rolling into a circle, measure the perimeter at 100 mm from the upper and lower mouths of the outer skin of the cylinder, and control the error L±5 mm, where L is the standard value of the outer skin perimeter uniformly specified after rolling into a circle and welding trial production. Further, carry out positioning assembly welding on the longitudinal seam according to the pile leg positioning welding process.

[0076] Further, weld the longitudinal seam. Lift the single-section cylinder to a simple jig by a lifting belt for (cylinder longitudinal seam) welding. The cylinder longitudinal seam uses carbon dioxide welding and submerged arc automatic welding. The back of the weld is buckled, and then lift the cylinder to a rolling tire jig and carry out construction according to the pile leg welding process.

[0077] Further, join two sections of the cylinder and then carry out the overall assembly of multiple sections of the cylinder, and finally make 4 new pile leg segments with a length of 10 meters.

[0078] Among them, the assembly requirements for joining two sections of the cylinder are: position according to the alignment line on the outer skin of the cylinder, measure the length after joining two sections of the cylinder, and the assembly length is the theoretical length. Then carry out assembly fixation on the circumferential seam. When joining the cylinders, the longitudinal seams of adjacent cylinders are misaligned by 180 degrees.

[0079] Further, joining the two cylinder sections is carried out on a rolling tire jig. The positioning reference is that the straightness deviation of the center line through the two cylinder sections is less than 1 mm (reflected by the straightness of the four equal division lines of the outer skin), and the 100-line spacing is 200±1 mm. Check the joining accuracy according to the table template. After being confirmed by the precision room and filed with the shipowner, it can be transferred to the next process for welding.

[0080] Further, the technical requirements for the circumferential welding of the cylinder body extension are as follows: For the inner side of the circumferential weld of the cylinder body extension, carbon dioxide gas shielded welding or submerged arc welding is used for backing welding; for other welds, submerged arc welding is used for filling and surfacing. It is fabricated on a rolling tire rack. Before welding, both sides of the weld need to be heated, and the preheating temperature range is 110 to 150 degrees Celsius. Before formal welding, the performance of the welding machine and the adjustment of process parameters need to be tested under the rolling tire rack. It is prohibited to place the test plate on the cylinder body. After the parameters are adjusted, the rotation speed of the rolling tire rack is adjusted according to the welding speed, and after the two are adjusted to match, formal welding is carried out.

[0081] Further, the assembly process of multiple sections of the cylinder body is as follows: The positioning reference cylinder body is placed on the tire rack, the cylinder body is segmented and butt-jointed for positioning, the circumferential joints of the cylinder body segments are assembled, the circumferential welds are welded, the circumferential welds are flaw-detected, the post-weld precision is measured, the outfitting parts are installed, and the leg segments are painted.

[0082] Further, the two cylinder bodies that have completed the extension are transported to the fabrication tire rack or the rolling tire rack for the leg segments in the outdoor yard.

[0083] Further, for the assembly of the leg cylinder body, the positioning reference is that the straightness deviation of the center line penetration of the two cylinder sections is less than 1 mm (reflected by the straightness of the four equal division lines of the outer skin), the line spacing of 100 lines is 200 ± 1 mm, and it is ensured that the height error of the adjacent cylinder outer skins (single side) is less than or equal to 1 mm. Further, the circumferential joints between segments are constructed according to the cylinder body (1 + 1 / 2 + 1) welding process. After the circumferential weld flaw detection is qualified, the excess height of the outer skin is ground flat, and the excess height is less than or equal to 1 mm. Among them, the post-weld precision requirements are as follows: The diameter tolerance is 4800 + 2 / -3 mm; the straightness is that the straightness error within any pile length of 19.5 m should not exceed 5 mm.

[0084] Further, 4 new pile shoes are prefabricated. The length, width, and height of the new pile shoes are 14.65 m, 12.45 m, and 4.8 m respectively, and the weight of a single new pile shoe is about 404 tons. During the prefabrication stage of the new pile shoes, the installation of sacrificial anodes, the punching system, outfitting parts, and other related work are carried out synchronously. After the prefabrication of the new pile shoes is completed, precision measurement, weld appearance inspection and flaw detection, and cabin tightness test are carried out. After the prefabrication of the new pile shoes is completed and inspected and reported for approval, overall painting is carried out.

[0085] The method for replacing the legs of the self-elevating wind power platform provided by the present invention divides the old legs into the first section of the old leg, the second section of the old leg, and the bottom old leg; the first section of the old leg is removed; the ship is steered into the dock, and the old pile shoe and the bottom old leg are removed; the ship is steered out of the dock, the fixing pile chamber on the second section of the old leg is taken out, and the second section of the old leg is removed; the ship is steered into the dock, the dock piers are arranged according to the preset drawings, the new pile shoe is placed on the temporary dock piers, and the crescent plate and the panel on the new pile shoe are installed; through the platform leg pin cylinder locking device, the bottom new leg is lowered and locked, and the position of the new pile shoe is adjusted; the ship is steered out of the dock, the first section of the new leg and the second section of the new leg are hoisted by a floating crane, and the joint between the legs is welded.

[0086] The method for replacing the leg of a jack-up wind power platform has the following advantages: the old leg is disassembled in sections, and the new leg is installed in sections, which reduces the requirements for the crane; different methods are used to disassemble different parts of the old leg, improving the disassembly efficiency of the old leg; the bottom new leg is locked by the locking device of the platform leg pin cylinder, improving the installation accuracy; after the first section of the old leg is removed, the old pile shoe is removed and transferred in the dock, and finally the second section of the old leg is removed, ensuring safety.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for replacing the leg of a jack-up wind power platform, characterized in that, Including: According to preset rules, sequentially divide the old pile legs into the first - section old pile legs, the second - section old pile legs, and the bottom old pile legs; The bottom old pile legs are the parts of the old pile legs connected to the old pile shoe; Demolish the first - section old pile legs; Steer the ship into the dock, and demolish the old pile shoe and the bottom old pile legs; Steer the ship out of the dock, take out the pile - fixing chamber on the second - section old pile legs, and demolish the second - section old pile legs; Steer the ship into the dock, arrange the dock piers according to the preset drawing, place the new pile shoe on the temporary dock piers, and install the crescent plate and the panel on the new pile shoe; Through the platform pile - leg pin oil - cylinder locking device, lower and lock the bottom new pile leg, adjust the position of the new pile shoe to align the positioning cross - marks of the new pile shoe and the bottom new pile leg; Steer the ship out of the dock, hoist the first - section new pile leg and the second - section new pile leg by a floating crane, and weld the joint between the pile legs.

2. The method for replacing the leg of a jack-up wind power platform according to claim 1, wherein The demolishing of the old pile shoe and the bottom old pile legs includes: Lower the remaining part of the old pile leg by a first preset distance through the lifting mechanism, and place wood between the bottom plate of the old pile shoe and the dock bottom; Fix the remaining part of the old pile leg through the pin of the lifting mechanism, and cut the barrel wall between the old pile leg and the old pile shoe to make the old pile shoe fall off; Demolish the pile leg with a first preset length under the bottom old pile leg, and lower the remaining part of the old pile leg by a second preset distance through the lifting mechanism; Demolish the pile leg with a second preset length under the bottom old pile leg, and raise the remaining part of the old pile leg by a third preset distance, that is, complete the demolition of the bottom old pile legs; Drain the water in the dry dock, move the old pile shoe to the dock entrance, that is, complete the demolition of the old pile shoe.

3. The method for replacing the leg of a jack-up wind power platform according to claim 1, wherein The hoisting of the second - section new pile leg by the floating crane includes: After hoisting the second - section new pile leg by the floating crane by a fourth preset distance, check the hook, signal, and control device of the floating crane, and check the lifting lugs and structure of the second - section new pile leg; After the second - section new pile leg is erected, remove the lifting ring at the lower end of the second - section new pile leg; Lift the second - section new pile leg by the floating crane and move the second - section new pile leg to the platform hoisting position; Adjust the front - back, left - right directions of the second - section new pile leg, the direction of the sectional positioning tooling, and lower it into the pile - leg general - section positioning tooling.

4. The method for replacing the leg of a jack-up wind power platform according to claim 1, wherein After welding the joint between the pile legs, it further includes: Conduct flaw detection on the welded part; Carry out platform pile insertion.

5. The jack-up wind power platform leg replacement method according to claim 1, characterized in that Before sequentially dividing the old pile legs into the first - section old pile legs, the second - section old pile legs, and the bottom old pile legs according to the preset rules, it further includes: Pre - fabricate the new pile legs in sections to obtain the first - section new pile legs and the second - section new pile legs; Pre - fabricate the new pile shoe and the bottom pile legs integrally.

6. The method for replacing the leg of a jack-up wind power platform according to claim 5, characterized in that, The pre - fabricating of the new pile legs in sections includes: Manufacture single - cylinder - section pile legs; Lengthen two single - cylinder - section pile legs, and then carry out multi - section cylinder assembly.

7. The method for replacing the leg of a jack-up wind power platform according to claim 6, characterized in that The process of the multi - section cylinder assembly includes: positioning the reference cylinder on the jig, butt - joint positioning of the cylinder sections, circumferential - joint assembly of the cylinder sections, circumferential - joint welding, circumferential - joint flaw detection, post - welding precision measurement, outfitting part installation, and pile - leg section painting.

8. The self-elevating wind power platform leg replacement method according to claim 5, characterized in that, The pre - fabricating of the new pile shoe includes: When prefabricating the new pile shoe, sacrificial anodes, a pile driving system, and outfitting components are installed synchronously.

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